Fluoride debate: The scientific evidence against fluoridation – Rita F. Barnett

By Ken Perrott 13/10/2014

Recently an unpublished paper by Rita F. Barnett, an associated professor of Legal Research and Writing at Chapman University, was heavily promoted by Paul Connett’s Fluoride Action Network and associated social media groups. Although basically a legal paper it did have a comprehensive section on the scientific  aspects of fluoridation.

Rita F. Barnett

She argued that the science indicated that community water fluoridation was neither effective or safe and was criticised for that. One of her critics, Daniel Ryan from the Making Sense of Fluoride group, participated in an exchange with her about the science.

As this has only been available in downloadable pdf format I am posting this exchange over the next few days as part of the ongoing fluoridation debate.

This post today is the section from Rita Barnett’s paper in which she argues that the science does not support community water fluoridation.

Scientific evidence against compulsory water fluoridation

(extract from Compulsory water fluoridation: Justifiable public health benefit or human experimental research without informed consent by Rita F. Barnett.)

Fluoridation proponents have historically characterized those opposing or questioning fluoridation as “irrational, fanatical, unscientific, or fraudulent,” regardless of the legitimate scientific credentials of those opposing fluoridation.64 However, the mounting scientific evidence against fluoridation has begun to persuade an increasing number of scientific researchers and dental and medical professionals, and even some formerly avid fluoride proponents.65

While a comprehensive review of all existing and emerging toxicological, clinical and epidemiological studies weighing against fluoridation or urging further research is beyond the purview of this article, a brief discussion of some current areas of concern follows.

1: Dental Fluorosis

Dental fluorosis occurs when children absorb too much fluoride. This excess fluoride “causes the biochemical signal to go awry, thereby creating gaps in the crystalline enamel structure.”66 When the tooth finally erupts, is it unevenly colored, and may even be pitted and brown.67

Although early fluoride proponents claimed that mild dental fluorosis was the only potential, and relatively rare, negative side effect to systemic fluoride exposure, today about 30-40% of American teenagers show visible signs of dental fluorosis, with the rate as high as 70-80% in some fluoridated areas.68

Exposure to multiple sources of fluoride beyond fluoridated water supplies may partly explain the higher than expected rates of dental fluorosis, the first sign of fluoride toxicity. Indeed, it is nearly impossible today to avoid consuming fluoride even in non-fluoridated areas, since fluoride is now found in fluoridated toothpaste, the pesticide residue on fresh produce, processed food and beverages made with fluoridated water, and many pharmaceuticals.69 Yet, research from the Iowa Fluoride Study, the largest long-running investigation on the effects of fluoride, has indicated that the most important risk factor for dental fluorosis is exposure to fluoridated water.70 Perhaps for this reason, the American Dental Association now recommends that parents use non-fluoridated water for infant baby formula, while the Institute of Medicine recommends that babies only consume a miniscule 10 micrograms of fluoride daily, a near impossible feat when babies are fed infant formula reconstituted with fluoridated water – even where levels are within the “optimal” range of 0.7- 1 ppm.71

Despite the fact that dental fluorosis not only produces unattractive teeth but may also increase the risk of tooth loss, the EPA and other U.S. public health officials downgraded even moderate to severe dental fluorosis from an adverse health effect to a purely cosmetic one.72 This downgrade has been largely perceived as a bow to political pressure rather than a legitimate health risk assessment.73 In any event, “it is widely acknowledged that dental fluorosis is a manifestation of systemic toxicity,” leading to far more serious health risks than unattractive teeth alone.74

2: Skeletal Fluorosis and Bone Fractures

Fluoride, of course, is not equipped with a smart GPS, able to provide benefits to teeth while bypassing bone and other organs of the human body.75 Instead, approximately 93% of ingested fluoride is absorbed into the bloodstream, and while some of it is excreted, roughly 50% is deposited into bone, potentially leading to skeletal fluorosis.76 Skeletal fluorosis is characterized by painful and limited joint movement, spinal deformities, muscle wasting, and calcification of the ligaments.77 Numerous studies have already linked skeletal fluorosis to excess fluoride intake, and although health officials had formerly insisted that skeletal fluorosis would not develop unless a person ingested 20 milligrams of fluoride per day for over 10 years, current research now suggests that doses as low as 6 mg/day can cause early stages of the disease, and that skeletal fluorosis can develop even with fluoride levels as low at 0.7 to 1.5 ppm, the range used in many fluoridation schemes throughout the United States.78 Unfortunately, skeletal fluorosis may go undetected or misdiagnosed because some of the symptoms mimic symptoms of arthritis or other bone diseases, and because many doctors do not know how to diagnose it.79

In addition to skeletal fluorosis, epidemiological studies have now also linked high fluoride exposure to an increase in bone fractures, especially in vulnerable populations such as the elderly and diabetics.80 Related studies have shown that people once given fluoride to “cure” osteoporosis wound up having increased fracture rates.81

3: Pineal Gland and Endocrine Disruption Studies

Researchers have now discovered that an even greater amount of fluoride accumulates in the pineal gland than in teeth and bone.82 The pineal gland is responsible for the synthesis and secretion of the hormone melatonin, which regulates the body’s circadian rhythm cycle and puberty in females, and helps to protect the body from cell damage from free radicals.83 While it is not yet known if fluoride accumulation affects pineal gland function in humans, experiments have already found that fluoride reduced melatonin levels, interfered with sleep-wake cycles, and shortened the time to puberty in animals.84

In addition, studies have now shown that fluoride can contribute to hypothyroidism (an underactive thyroid), which is unsurprising, since fluoride was once used as a prescription drug to reduce thyroid gland function in patients with hyperthyroidism (an overactive thyroid).85 The fluoride dose capable of reducing thyroid function is low – just 2 to 5 mg per day over several months. This is well within the range of what individuals living in fluoridated communities are receiving on a regular basis.86

4: Cancer Studies

Numerous studies have now suggested a link between cancer and fluoride.87 However, perhaps even more disturbing than the evidence supporting the fluoride-cancer link is the evidence suggesting that political and other agendas have played a large part in the outright suppression of this evidence.88

First, in the early 1950’s, Dr. Alfred Taylor, a biochemist at the University of Texas, conducted a series of experiments in which cancer prone mice consuming water treated with sodium fluoride were found to have shorter lifespans than cancer-prone mice drinking non-fluoridated water.89 After discovering that his first round of tests had been contaminated because both groups of mice had eaten food containing fluoride, Dr. Taylor repeated the experiment, and found the same results – a shorter life span for the mice drinking the fluoridated water. However, because these damaging results appeared around the launch time of the early fluoridation schemes, and because public health officials had already come out in staunch support of fluoridation, Dr. Taylor’s work was misrepresented. Specifically, fluoridation proponents falsely claimed that Dr. Taylor had never conducted the second study revealing that the fluoride-cancer link was still present when the necessary controls were put in place.90

Then, in 1990, a study conducted by the U.S. government’s National Toxicology Program (“NTP”) found a positive relation for osteosarcoma (bone cancer) in male rats exposed to different amounts of fluoride in drinking water.91 When NTP downplayed the results in order to avoid a public outcry over compulsory fluoridation, a storm of controversy erupted, with a number of scientists outraged at the failure to report the cancer linked results accurately.92

Finally, in 2006, Elise Bassin and her colleagues at the Harvard School of Dental Medicine published a study in the peer-reviewed journal Cancer Causes and Control, which also showed a link between fluoridation and osteosarcoma in young men.93 Incredibly, Bassin’s own dissertation advisor at Harvard, Chester Douglass, wrote a commentary in the same journal warning readers to be “especially cautious” about Bassin’s results. This lead to yet another controversy, with Bassin’s defenders calling for an ethical investigation of Douglass, since, as it turned out, Douglass had some conflicts of interest and was the editor in chief of a newsletter for dentists funded by Colgate. 94

5: Lower IQ’s in Children

Researchers have also begun to focus on the damaging effects fluorides appear to have on the human brain. In the 1990’s, researcher Phyllis Mullenix studied the brain and behavioral effects of sodium fluoride on rats.95 Her study revealed that pre-natal exposure to fluoride correlated with life-long hyperactivity in young rats, while post-natal exposures often had the opposite, “couch potato” effect.96 Although Mullenix’s research was published in a well-respected peer reviewed journal, the fluoride proponents attacked her methodology and declared her results flawed.97 Since then, however, forty-six other studies have emerged showing a connection between excess exposure to fluoride and lowered IQ’s in children, with 39 of the 46 finding that elevated fluoride exposure is associated with decreased IQ, and 29 of the 31 animal studies showing that fluoride exposure impairs the learning and/or memory capacity of animals.98

In 2012, after conducting a meta-analysis of 27 of the fluoride-human IQ studies, conducted mostly in China, a team of scientists from Harvard’s School of Public Health and China’s Medical University in Shenyang concluded that the studies suggested an average IQ decrease of about seven points in children exposed to raised fluoride concentrations.99 In 2014, one of the chief authors of the initial 2012 meta-analysis, Harvard professor Philippe Grandjean, concluded in a follow-up article that “our very great concern is that children worldwide are being exposed to unrecognized toxic chemicals that are silently eroding intelligence,” and that fluoride’s effect on the young brain should now be a “high research priority.”100 Notably, a majority of the 27 studies analyzed were of water fluoride levels of less than 4 mg/L, which falls under the allowable concentrations of fluoride under current EPA regulations.101

6: Benefits from Systemic Fluoride Intake?

With so many current studies linking fluoride to serious health risks beyond dental fluorosis, the question remains whether fluoride’s public health benefits outweigh any and all of these risks. The Centers for Disease Control has deemed water fluoridation one of the “top ten health achievements of the 20th Century.”102 Proponents therefore insist that even if there are a number of recognized risks of fluoridation, there has been enough evidence to show that these risks are remote and are far outweighed by the benefits.103 Yet much of the available scientific data today suggests that any benefit from fluoride in terms of preventing tooth decay has been from topical application, rather than systemic ingestion.104 Moreover, even the benefits of topical fluoride treatments have been recently questioned, since most dental caries today are in the “pits and fissures” of the molars rather than on the flat surface of teeth, and various studies have now indicated that fluoride has no impact on the pits and fissures.105

Research conducted over the last twenty years has also shown that the estimated reduction in tooth decay due to compulsory water fluoridation has been grossly exaggerated. While at one time proponents boasted a 50-65% reduction in tooth decay, a great deal of current evidence suggests the real percentage is significantly lower, with some studies showing no measurable reduction at all. 106 Confounding claims of benefit even further, numerous studies have shown a substantially similar decline in the dental caries rate in countries that do not fluoridate, and in areas within the United States that remain unfluoridated.107

Nor have the asserted economic benefits of compulsory water fluoridation come to fruition. In fact, a number of economic evaluation studies have indicated that the costs of dental care may actually be higher in fluoridated communities than in non-fluoridated communities.108

Unfortunately, rather than considering the new data objectively, public health officials and dental lobbies spearheading fluoridation schemes often ignore, reject, or suppress the evidence that does not toe the pro-fluoride party line.109 Nevertheless, as evidence against fluoridation continues to 20 Compulsory Water Fluoridation [23 Sept 14 accumulate in a variety of health risk areas, two conclusions seem readily apparent. First, there remain significant unanswered questions about the risks and benefits of systemic fluoride, and further research before imposing or continuing fluoridation schemes seems not only scientifically prudent, but ethically necessary. Second, it is no longer acceptable for public health officials to simply dismiss the accruing negative data and to continue to insist that the levels of fluoride children and adults are receiving on a daily basis are without any serious health consequences. Fortunately, tentative moves by the EPA and other federal agencies suggest that at least some public health authorities are inching towards similar conclusions.


64 See e.g. Hileman, supra note 18, at 4. See also Graham, supra note 17, at 195 (noting a pro-fluoridation report characterizing fluoride opponents as follows: “The opposition stems from several sources, chiefly food faddists, cultists, chiropractors, misguided and misinformed persons who are ignorant of the scientific facts on the ingestion of water fluorides, and, strange as it may seem, even among a few uniformed physicians and dentists.”). See also Leila Barraza, Daniel G. Orenstein, Doug Campos- Outcalt, Denialism and Its Adverse Effect on Public Health, 53 JURIMETRICS J. 307, 307 (calling those who oppose fluoridation “denialists” who “misuse science to advocate positions that contradict the overwhelming weight of existing evidence”).

65 See e.g., John Colquhoun, Why I Changed My Mind About Water Fluoridation, 41 PERSPECTIVES IN BIOLOGY AND MEDICINE 1 (1997); Dr. Hardy Limeback, Why I Am Now Officially Opposed to Adding Fluoride to Drinking Water, FLUORIDE ACTION NETWORK (April 2000), http://fluoridealert.org/articles/limeback/; J. William Hirzy, Dr. William Hirzy, Former Head of EPA’s Headquarters Union Recommends Portland Flush Fluoridation Proposal (March 2013), FLUORIDE ACTION NETWORK, http://fluoridealert.org/content/hirzy_portland/.

66 Fagin, supra note 26, at 78.

67 Fagin, supra note 26, at 78; Hileman, supra note 18, at 9.

68 See Beltran-Aguilar, et. al., Prevalence and Severity of Dental Fluorosis in the United States, 1999-2004, NCHS DATA BRIEF NO. 53 (2010), http://www.cdc.gov/nchs/data/databriefs/db53.pdf. See also Czajka, supra note 13, at 125.

69 Beltran-Aguilar, supra note 68; Peckham, supra note 13, at 165.

70 Fagin, supra note 26, at 79 (children exposed to fluoridated water were 50% more likely to have dental fluorosis than children living in non-fluoridated areas).

71 Peckham, supra note 13, at 165-66.

2 See Hileman, supra note 18 at 10.

73 Id.

74 Peckham, supra note 13, at 166.

75 Limeback, supra note 65 (“it is illogical to assume that tooth enamel is the only tissue affected by low daily doses of fluoride ingestion.”); Colquhoun, supra note 65 (“Common sense should tell us that if a poison circulating in a child’s body can damage the tooth-forming cells, then other harm also is likely.”).

76 Czajka, supra note 13 at 125.

77 Null, supra note 17, at 74.

78 Czajka, supra note 13, at 125.

79 Null, supra note 17, at 74; Hileman, supra note 18, at 13.

80 Fagin, supra note 26, at 79.

81 See Null, supra note 17, at 74-75.

82 Jennifer Luke, Fluoride Deposition in the Aged Human Pineal Gland, 35 CARIES RESEARCH 125-128 (2001). See also Czajka, supra note 13, at 126.

83 Fluoride Action Network, Pineal Gland, FLUORIDEALERT.ORG, http://fluoridealert.org/issues/health/pineal-gland/ (last visited June 25, 2014) (discussing/listing pineal gland studies).

84 Id.

85Fluoride Action Network, Thyroid, FLUORIDEALERT.ORG, http://fluoridealert.org/issues/health/thyroid/ (last visited June 25, 2014) (discussing/listing numerous thyroid studies).

86 Null, supra note 17, at 71. See also Fluoride Action Network, Endocrine, FLUORIDEALERT.ORG, http://fluoridealert.org/issues/health/endocrine/(last visited June 25, 2014) (discussing/listing numerous endocrine system studies).

87 Fluoride Action Network, Cancer, FLUORIDEALERT.ORG, http://fluoridealert.org/issues/health/cancer/ (last visited June 25, 2014) (discussing/listing numerous cancer studies).

88 See e.g., Null, supra note 17, at 77; Graham, supra note 17, at 229-240.

89 Null, supra note 17, at 77.

90 Id.

91 NTP Toxicology and Carcinogenesis Studies of Sodium Fluoride in F344/N Rats and B6C3F1 Mice (Drinking Water Studies), 393 NATL. TOXICOL. PROGRAM TECH REP SERV. 1-448 (1990).

92 Null, supra note 17, at 78-79.

93 E. B. Bassin et. al., Age Specific Fluoride Exposure in Drinking Water and Osteosarcoma, 17 CANCER CAUSES & CONTROL 421-28 (2006) (finding an association between fluoride exposure in drinking water during childhood and the incidence of osteosarcoma among males but not consistently among females). See also S Kharb et. al., Fluoride Levels and Osteosarcoma, 1 SOUTH ASIAN J. CANCER 76-77 (2012) (finding positive correlation between fluoride and osteosarcoma).

94 Fagin, supra note 26, at 80. 95 Phyllis J. Mullenix, Neurotoxicity of Sodium Fluoride in Rats, 17 NEUROTOXICOLOGY AND TERATOLOGY 169-177 (1995).

96Fagin, supra note 26, at 80. See also Null, supra note 17, at 74 (describing an ad campaign promoting a fluoridated spring water “for kids who can’t sit still.”).

97 Fagin, supra note 26, at 80.

98 Fluoride Action Network, Brain, FLUORIDEALERT.ORG, http://fluoridealert.org/issues/health/brain/ (last visited June 25, 2014) (discussing/listing numerous brain studies).

99 See Anna L. Choi et. al, Developmental Fluoride Neurotoxicity: A Systematic Review and Meta-Analysis, 120 ENVIRON. HEALTH PERSPECT. 1362-1368 (2012).

100 Philippe Grandjean & Philip Landrigan, Neurobehavioural Effects of Developmental Toxicity, 13 THE LANCET NEUROLOGY, 330-338 (2014) (“untested chemicals should not be presumed to be safe to brain development, and chemicals in existing use and all new chemicals must therefore be tested for developmental neurotoxicity.”). See also Diana Rocha-Amador, Decreased Intelligence in Children and Exposure to Fluoride and Arsenic in Drinking Water, Cad. Saude Publica, Rio de Janeiro, 23 Sup. S579-587 (2007).

101 See discussion infra Sec. III.

102 CDC FLUORIDATION, supra note 18.

103 Hileman, supra note 18, at 2.

104 See Czajka, supra note 13, at 127.

105 See e.g., Letter from Dr. Paul Connett to Scientific Committee on Health and Environmental Risks, the European Committee, at #7 (March 30, 2009), available at http://www.fluoridealert.org/wp-content/uploads/scher.march_.2009.pdf (“Since 1950, it has been found that fluorides do little to prevent pit and fissure tooth decay…This is significant because pit and fissure tooth decay represents up to 85% of the tooth decay experienced by children today.”).

106 Hileman, supra note 18, at 5.

107 Hileman, supra note 18, at 6-7. See also Michael Connett, Tooth Decay Trends in Fluoridated vs. Unfluoridated Countries (March 2012), FLUORIDEALERT.ORG, http://fluoridealert.org/studies/caries01/ (noting that decay rates in non-fluoridated countries have declined at the same rate as those in fluoridated countries).

108 Hileman, supra note 18, at 7. 109 See e.g., Voices of Opposition Have Been Suppressed Since Early Days of  Fluoridation, CHEMICAL & ENGINEERING NEWS (August 1, 1988), available at


Daniel Ryan’s first response to Rita’s unpublished paper will be posted tomorrow – see Fluoride debate: A response to Rita Barnett-Rose – Daniel Ryan

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